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29 Mar 2004

Volume 84, Issue 13, pp. 2223-2459

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Appl. Phys. Lett. 84, 2244 (2004); http://dx.doi.org/10.1063/1.1690471 (3 pages)

David R. Smith, David Schurig, Jack J. Mock, Pavel Kolinko, and Patrick Rye
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Energetic stability and magnetic properties of Mn dimers in silicon

F. Bernardini, S. Picozzi, and A. Continenza

Appl. Phys. Lett. 84, 2289 (2004); http://dx.doi.org/10.1063/1.1688002 (3 pages) | Cited 30 times

Online Publication Date: 23 March 2004

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We present an accurate first-principles study of magnetism and energetics of single Mn impurities and Mn dimers in Si. Our results, in general agreement with available experiments, show that (i) Mn atoms tend to aggregate, the formation energy of dimers being lower than the sum of the separate constituents, (ii) ferromagnetic coupling is favored between the Mn atoms constituting the dimers in p-type Si, switching to an antiferromagnetic coupling in n-type Si, (iii) Mn atoms show donors (acceptor) properties in p-type (n-type) Si, therefore they tend to compensate doping, while dimers being neutral or acceptors allow for Si to be doped p-type. © 2004 American Institute of Physics.
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71.55.Cn Elemental semiconductors
75.30.Cr Saturation moments and magnetic susceptibilities
75.20.Hr Local moment in compounds and alloys; Kondo effect, valence fluctuations, heavy fermions

Effects of high-dose Mn implantation into ZnO grown on sapphire

Y. W. Heo, M. P. Ivill, K. Ip, D. P. Norton, S. J. Pearton, J. G. Kelly, R. Rairigh, A. F. Hebard, and T. Steiner

Appl. Phys. Lett. 84, 2292 (2004); http://dx.doi.org/10.1063/1.1690111 (3 pages) | Cited 98 times

Online Publication Date: 23 March 2004

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ZnO films grown by pulsed-laser deposition on c-plane Al2O3 substrates were annealed at temperatures up to 600 °C to produce n-type carrier concentrations in the range 7.5×1015–1.5×1020 cm−3. After high-dose (3×1016 cm−2) Mn implantation and subsequent annealing at 600 °C, all the films show n-type carrier concentrations in the range 2–5×1020 cm−3 and room temperature hysteresis in magnetization loops. The saturation magnetization and coercivity of the implanted single-phase films were both strong functions of the initial anneal temperature, suggesting that carrier concentration alone cannot account for the magnetic properties of ZnO:Mn, and that factors such as crystalline quality and residual defects play a role. © 2004 American Institute of Physics.
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61.72.uj III-V and II-VI semiconductors
81.15.Fg Pulsed laser ablation deposition
75.50.Pp Magnetic semiconductors
75.60.Ej Magnetization curves, hysteresis, Barkhausen and related effects
72.20.Fr Low-field transport and mobility; piezoresistance

Single carrier localization in InxGa1−xAs1−yNy investigated by magnetophotoluminescence

A. Polimeni, F. Masia, A. Vinattieri, G. Baldassarri Höger von Högersthal, and M. Capizzi

Appl. Phys. Lett. 84, 2295 (2004); http://dx.doi.org/10.1063/1.1688003 (3 pages) | Cited 5 times

Online Publication Date: 23 March 2004

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We investigated the origin of radiative recombination in InxGa1−xAs1−yNy/GaAs quantum wells by photoluminescence (PL) after picosecond excitation and under a magnetic field, B. Continuous wave and time-resolved PL show that at low temperature T localized states are mainly involved in the radiative recombination processes. Most importantly, the shift of the PL peak position induced by B depends dramatically on temperature, being higher at lower T. This result indicates that the PL emission at low temperature is determined by the recombination of loosely bound electron-hole pairs in which one carrier is localized by N-induced potential fluctuations, and the other carrier is delocalized. © 2004 American Institute of Physics.
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73.21.Fg Quantum wells
73.20.Fz Weak or Anderson localization
72.20.Jv Charge carriers: generation, recombination, lifetime, and trapping
78.55.Cr III-V semiconductors
78.47.-p Spectroscopy of solid state dynamics
78.20.Ls Magneto-optical effects

Electron mobility in ultrathin silicon-on-insulator layers at 4.2 K

M. Prunnila, J. Ahopelto, and F. Gamiz

Appl. Phys. Lett. 84, 2298 (2004); http://dx.doi.org/10.1063/1.1687980 (3 pages) | Cited 7 times

Online Publication Date: 23 March 2004

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Low temperature mobility measurements of silicon-on-insulator (SOI) metal-oxidefield-effect-transistors are reported. The batch of devices fabricated in this work includes both ultrathin and thick devices for which the SOI film thicknesses are in the ranges of 10–15 nm and 56–61 nm, respectively. The 4.2 K peak mobility of the thick devices is 1.9 m2/V s. The ultrathin devices show mobility degradation at low electron densities where the mobility is also observed to decrease with decreasing the SOI film thickness. The peak mobilities of these devices are in the range of 1.35–1.57 m2/V s. Numerical calculations show that ultrathin devices are in the limit where the electrons are confined by the quantum well defined by gate oxide and buried oxide, which is interpreted to lead to the observed mobility degradation. © 2004 American Institute of Physics.
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73.40.Qv Metal-insulator-semiconductor structures (including semiconductor-to-insulator)
85.30.Tv Field effect devices

Enhanced thermoelectric figure of merit of CoSb3 via large-defect scattering

X. Shi, L. Chen, J. Yang, and G. P. Meisner

Appl. Phys. Lett. 84, 2301 (2004); http://dx.doi.org/10.1063/1.1687997 (3 pages) | Cited 41 times

Online Publication Date: 23 March 2004

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We have measured the structural, chemical, and transport properties of a series of CoSb3 skutterudite samples modified by fullerene additions of 0, 0.52, 3.28, 3.90, 4.77, and 6.54 mass%. Fullerene is a 60-atom carbon molecule that forms microsize clusters between the grain boundaries of CoSb3. We observed that the dominant scattering mechanism in the electrical transport changes from impurity scattering to grain-boundary scattering near a C60 content of ∼5–6 mass%, and that thermal conductivity decreases with increasing C60 content. A significant increase in the thermoelectric figure of merit is achieved for 6.54 mass% C60 compared to the pure CoSb3. © 2004 American Institute of Physics.
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72.15.Jf Thermoelectric and thermomagnetic effects
72.15.Eb Electrical and thermal conduction in crystalline metals and alloys
61.72.Mm Grain and twin boundaries
72.15.Qm Scattering mechanisms and Kondo effect

Tuning the electrical resistivity of pulsed laser deposited TiSiOx thin films from highly insulating to conductive behaviors

D. Brassard, D. K. Sarkar, M. A. El Khakani, and L. Ouellet

Appl. Phys. Lett. 84, 2304 (2004); http://dx.doi.org/10.1063/1.1688999 (3 pages) | Cited 8 times

Online Publication Date: 23 March 2004

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We report on the successful growth of amorphous TiSiOx thin films by means of pulsed-laser ablation of a TiO2/SiO2 composite target in a high-vacuum chamber. The room-temperature resistivity of the TiSiOx films is found to decrease by more than 6 orders of magnitude (i.e., from ∼ 2×104 to 10−2 Ω cm) when their substrate deposition temperature (Td) is increased from 20 to 600 °C. On the other hand, by subjecting these films to a post-deposition annealing at 600 °C in oxygen atmosphere, they become highly insulating with a resistivity level as high as 2×1010 Ω cm, regardless of the Td value. The presence of conductive titanium silicide and titanium sub-oxide local phases in the as-deposited TiSiOx films, as revealed by photoelectron spectroscopy analyses, appears to be the cause of the observed tremendous change in the film resistivity. In particular, it is shown that the resistivity of the TiSiOx films is strongly correlated with their oxygen content. © 2004 American Institute of Physics.
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73.61.Ng Insulators
81.15.Fg Pulsed laser ablation deposition
81.40.Ef Cold working, work hardening; annealing, post-deformation annealing, quenching, tempering recovery, and crystallization
72.60.+g Mixed conductivity and conductivity transitions
79.60.-i Photoemission and photoelectron spectra

A spin metal–oxide–semiconductor field-effect transistor using half-metallic-ferromagnet contacts for the source and drain

Satoshi Sugahara and Masaaki Tanaka

Appl. Phys. Lett. 84, 2307 (2004); http://dx.doi.org/10.1063/1.1689403 (3 pages) | Cited 96 times

Online Publication Date: 23 March 2004

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We propose and theoretically analyze a metal–oxide–semiconductor field-effect-transistor (MOSFET) type of spin transistor (spin MOSFET) consisting of a MOS structure and half-metallic-ferromagnet (HMF) contacts for the source and drain. When the magnetization configuration of the HMF source and drain is parallel (antiparallel), highly spin-polarized carriers injected from the HMF source to the channel are transported into (blocked by) the HMF drain, resulting in the magnetization-configuration-dependent output characteristics. Our two-dimensional numerical analysis indicates that the spin MOSFET exhibits high (low) current drive capability in the parallel (antiparallel) magnetization, and that extremely large magnetocurrent ratios can be obtained. Furthermore, the spin MOSFET satisfies other important requirements for “spintronic integrated circuits,” such as high amplification capability, low power-delay product, and low off-current. © 2004 American Institute of Physics.
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85.75.Hh Spin polarized field effect transistors
72.20.Fr Low-field transport and mobility; piezoresistance
85.40.Ls Metallization, contacts, interconnects; device isolation
72.25.Hg Electrical injection of spin polarized carriers
85.30.De Semiconductor-device characterization, design, and modeling

Mn-implanted dilute magnetic semiconductor InP:Mn

Yoon Shon, W. C. Lee, Y. S. Park, Y. H. Kwon, Seung Joo Lee, K. J. Chung, H. S. Kim, D. Y. Kim, D. J. Fu, T. W. Kang, X. J. Fan, Y. J. Park, and H. T. Oh

Appl. Phys. Lett. 84, 2310 (2004); http://dx.doi.org/10.1063/1.1690875 (3 pages) | Cited 17 times

Online Publication Date: 23 March 2004

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Unintentionally doped bulk InP was prepared by the liquid encapsulated Czochralski method and subsequently implanted with various doses of Mn+. The properties of Mn+-implanted InP:Mn were investigated by various measurements. The results of energy dispersive x-ray peaks displayed injected concentrations of Mn of 0.8% and 8.8%, respectively. The results of photoluminescence (PL) measurement showed that optical broad transitions related to Mn appeared near 1.089, 1.144, and 1.185 eV in samples with various doses of Mn+. It was confirmed that the photoluminescence peaks near 1.089, 1.144, and 1.185 eV were Mn-correlated PL bands by the implantation of Mn. Ferromagnetic hysteresis loops measured at 10 K were observed and the temperature-dependent magnetization showed ferromagnetic behavior around 90 K, which almost agreed with the theoretical prediction (Tc ∼ 70 K). © 2004 American Institute of Physics.
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75.50.Pp Magnetic semiconductors
75.50.Dd Nonmetallic ferromagnetic materials
75.60.Ej Magnetization curves, hysteresis, Barkhausen and related effects
78.55.Cr III-V semiconductors
81.10.Fq Growth from melts; zone melting and refining
82.80.Ej X-ray, Mössbauer, and other γ-ray spectroscopic analysis methods

Electron transport properties in AlGaN/InGaN/GaN double heterostructures grown by metalorganic vapor phase epitaxy

C. X. Wang, K. Tsubaki, N. Kobayashi, T. Makimoto, and N. Maeda

Appl. Phys. Lett. 84, 2313 (2004); http://dx.doi.org/10.1063/1.1690879 (3 pages) | Cited 14 times

Online Publication Date: 23 March 2004

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Electron transport properties in AlGaN/InGaN/GaN double heterostructures have been investigated. Samples were grown by metalorganic vapor phase epitaxy and evaluated using x-ray diffraction and variable temperature Hall effect measurements. Much higher two-dimensional electron gas density of up to 50% has been obtained in AlGaN/InGaN/GaN structure than in a typical AlGaN/GaN structure due to the larger polarization effect while the mobilities are comparable at room temperature and above in these structures, which demonstrates the suitability of an AlGaN/InGaN/GaN structure for high-power device applications. Theoretical simulations were done to investigate the carrier transport mechanism, and they suggest that alloy disorder and interface roughness scattering have a very strong impact on the electron transport properties in AlGaN/InGaN/GaN structures. © 2004 American Institute of Physics.
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81.05.Ea III-V semiconductors
73.50.Jt Galvanomagnetic and other magnetotransport effects (including thermomagnetic effects)
81.15.Kk Vapor phase epitaxy; growth from vapor phase
68.35.Ct Interface structure and roughness
68.55.A- Nucleation and growth
73.61.Ey III-V semiconductors

Dependence of leakage mechanisms on dielectric barrier in Cu–SiOC damascene interconnects

V. C. Ngwan, Chunxiang Zhu, and Ahila Krishnamoorthy

Appl. Phys. Lett. 84, 2316 (2004); http://dx.doi.org/10.1063/1.1688978 (3 pages) | Cited 6 times

Online Publication Date: 23 March 2004

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Leakage mechanisms of low-dielectric constant (low-k) carbon-doped silicon oxide (SiOC) were investigated in Cu damascene structure integrated with amorphous SiC or SiN as Cu diffusion barrier at low electric fields (0–1.36 MV/cm) and various temperatures (25–250 °C). Conduction mechanisms of SiOC integrated with SiC were found to be different from that with SiN. Schottky emission over a barrier height of 0.70 eV at Ta/SiOC interface dominates in SiC–SiOC structures while Poole–Frenkel emission over a trap potential well of 0.69 eV dominates in SiN–SiOC structures. Traps in the SiN/SiOC interface are the main sources of leakage in Cu low-k damascene structures with SiN barrier. © 2004 American Institute of Physics.
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85.40.Ls Metallization, contacts, interconnects; device isolation
77.22.Ch Permittivity (dielectric function)
68.35.Fx Diffusion; interface formation
73.50.Fq High-field and nonlinear effects

Energy band alignment at the (100)Ge/HfO2 interface

V. V. Afanas’ev and A. Stesmans

Appl. Phys. Lett. 84, 2319 (2004); http://dx.doi.org/10.1063/1.1688453 (3 pages) | Cited 56 times

Online Publication Date: 23 March 2004

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The Ge/HfO2 interface band diagram was directly determined using internal photoemission of electrons and holes from Ge into the Hf oxide. The inferred offsets of the conduction and valence band at the interface, 2.0±0.1 and 3.0±0.1 eV, respectively, suggest the possibility to apply the deposited HfO2 as an insulator on Ge. The post-deposition annealing of the Ge/HfO2 structures in oxygen results in ∼1 eV reduction of the valence band offset attributed to the growth of GeO2 interlayer. © 2004 American Institute of Physics.
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84.32.Tt Capacitors
79.60.Jv Interfaces; heterostructures; nanostructures
68.35.Ct Interface structure and roughness
73.20.At Surface states, band structure, electron density of states
61.72.Cc Kinetics of defect formation and annealing

Temperature dependence of electron impact ionization in In0.53Ga0.47As

C. H. Tan, G. J. Rees, P. A. Houston, J. S. Ng, W. K. Ng, and J. P. R. David

Appl. Phys. Lett. 84, 2322 (2004); http://dx.doi.org/10.1063/1.1691192 (3 pages) | Cited 10 times

Online Publication Date: 23 March 2004

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Monte Carlo is used to model the electric field and temperature dependence of the electron ionization coefficient, α, in In0.53Ga0.47As, using a two-component ionization rate to account for its observed anomalous dependence on the electric field. α is predicted to decrease with temperature at fields above approximately 180 kV/cm, where impact ionization is limited by the high-energy electron population, and to increase with temperature at lower fields, where it is enhanced by the decreasing ionization threshold energy, in agreement with experimental observations. © 2004 American Institute of Physics.
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72.20.Ht High-field and nonlinear effects
72.80.Ey III-V and II-VI semiconductors

Current conduction processes in high-κ Gd0.31Ga0.1O0.59/Ga2O3 gate dielectric stacks on GaAs

A. Chen, M. Passlack, N. Medendorp, and D. Braddock

Appl. Phys. Lett. 84, 2325 (2004); http://dx.doi.org/10.1063/1.1687999 (3 pages) | Cited 6 times

Online Publication Date: 23 March 2004

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Current conduction processes in high-κ (κ = 20.2) Gd0.31Ga0.1O0.59/Ga2O3 dielectric stacks grown on n-type GaAs by molecular beam epitaxy have been investigated. Metal-oxide-semiconductor capacitors have been characterized by current density (j) versus electric field (E) measurements at temperatures ranging from 90 to 450 K. For temperatures T ⩽ 200 K, the high field (4.5 ⩽ E ⩽ 6.2 MV/cm) current is temperature independent and a Fowler–Nordheim tunneling slope of 1.75 eV3/2 is obtained. Frenkel–Poole emission is found to dominate at temperatures of 300 K and above at moderate electric fields (1.3 ⩽ E ⩽ 2.2 MV/cm). For Frenkel–Poole emission, a barrier height of 1.1 eV and a dynamic dielectric constant of 7.95 is derived from ln(j/E) vs 1/T and ln(j/E) vs E1/2 plots, respectively. © 2004 American Institute of Physics.
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77.55.-g Dielectric thin films
73.40.Qv Metal-insulator-semiconductor structures (including semiconductor-to-insulator)
72.20.Ht High-field and nonlinear effects
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
84.32.Tt Capacitors

Effects of interlayer and annealing on chemical states of HfO2 gate insulators studied by photoemission spectroscopy

S. Toyoda, J. Okabayashi, H. Kumigashira, M. Oshima, K. Ono, M. Niwa, K. Usuda, and G. L. Liu

Appl. Phys. Lett. 84, 2328 (2004); http://dx.doi.org/10.1063/1.1689393 (3 pages) | Cited 31 times

Online Publication Date: 23 March 2004

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We have performed photoemission spectroscopy of high-k gate insulators HfO2/HfSiON/Si to investigate the interlayer formation by Hf metal predeposition and the annealing effect systematically. Comparing the line shapes of core-level photoemission spectra for two systems with and without Hf-metal predeposition, we found that Hf-metal predeposition effectively reduces the growth of interface layer. Hf 4f core-level spectra revealed that the annealing at 1000 °C for both samples causes the formation of the metallic Hf and Hf-silicide clusters. Surface morphology was also observed by atomic force microscopy. © 2004 American Institute of Physics.
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79.60.Bm Clean metal, semiconductor, and insulator surfaces
77.22.Ch Permittivity (dielectric function)
73.20.Fz Weak or Anderson localization
73.40.Qv Metal-insulator-semiconductor structures (including semiconductor-to-insulator)
77.84.Bw Elements, oxides, nitrides, borides, carbides, chalcogenides, etc.
68.35.B- Structure of clean surfaces (and surface reconstruction)
68.37.Ps Atomic force microscopy (AFM)
81.40.Gh Other heat and thermomechanical treatments

Terahertz emission by plasma waves in 60 nm gate high electron mobility transistors

W. Knap, J. Lusakowski, T. Parenty, S. Bollaert, A. Cappy, V. V. Popov, and M. S. Shur

Appl. Phys. Lett. 84, 2331 (2004); http://dx.doi.org/10.1063/1.1689401 (3 pages) | Cited 87 times

Online Publication Date: 23 March 2004

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We report on the resonant, voltage tunable emission of terahertz radiation (0.4–1.0 THz) from a gated two-dimensional electron gas in a 60 nm InGaAs high electron mobility transistor. The emission is interpreted as resulting from a current driven plasma instability leading to oscillations in the transistor channel (Dyakonov–Shur instability). © 2004 American Institute of Physics.
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85.30.Tv Field effect devices
72.20.Fr Low-field transport and mobility; piezoresistance
72.30.+q High-frequency effects; plasma effects
85.30.De Semiconductor-device characterization, design, and modeling

Organic phototransistor based on intramolecular charge transfer in a bifunctional spiro compound

Tobat P. I Saragi, Robert Pudzich, Thomas Fuhrmann, and Josef Salbeck

Appl. Phys. Lett. 84, 2334 (2004); http://dx.doi.org/10.1063/1.1690110 (3 pages) | Cited 65 times

Online Publication Date: 23 March 2004

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We report on the fabrication of organic phototransistors based on the spiro-conjugated molecule 2,7-bis-(N,N′-diphenylamino)-2′,7′-bis(biphenyl-4-yl)-9,9′-spirobifluorene. Intramolecular charge transfer leads to an increase in charge carrier density, providing the amplification effect. The sensitivity is better than 1 A/W for ultraviolet light at 370 nm, making the device interesting for sensor applications. © 2004 American Institute of Physics.
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85.60.Dw Photodiodes; phototransistors; photoresistors
82.30.Fi Ion-molecule, ion-ion, and charge-transfer reactions

Thickness-dependent metal–insulator transition in V2O3 ultrathin films

Qiang Luo, Qinlin Guo, and E. G. Wang

Appl. Phys. Lett. 84, 2337 (2004); http://dx.doi.org/10.1063/1.1690107 (3 pages) | Cited 14 times

Online Publication Date: 23 March 2004

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In this study, V2O3 ultrathin films about 5–20 nm thick were prepared on Al2O3 (0001) substrates through a reactive evaporation process. Auger electron spectroscopy and x-ray photoelectron spectroscopy have been used in situ to characterize their compositions and chemical states. Electric resistance measurements show that V2O3 films transform from metallic to semiconducting with the decrease of film thickness, which results from the a1g level rising because the lattice mismatch between the substrate and the film expands the c/a parameter ratio. No temperature-induced metal–insulator transition (like that in bulk V2O3) was observed in V2O3 thin films at low temperature. We conclude that stress plays a major role in suppressing the temperature-induced metal–insulator transition. © 2004 American Institute of Physics.
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71.30.+h Metal-insulator transitions and other electronic transitions
68.55.-a Thin film structure and morphology
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
79.60.-i Photoemission and photoelectron spectra
79.20.Fv Electron impact: Auger emission
73.61.Ng Insulators
72.80.Sk Insulators

Polarization-induced electron island in semiconductor grain placed into pyroelectric matrix

V. Yu. Kachorovskii and M. S. Shur

Appl. Phys. Lett. 84, 2340 (2004); http://dx.doi.org/10.1063/1.1691197 (3 pages) | Cited 7 times

Online Publication Date: 23 March 2004

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We consider the electron distribution in an n-type semiconductor grain inserted into a pyroelectric matrix. We show that for typical values of parameters, the electric field induced in the grain by the pyroelectric spontaneous polarization is very strong and cannot be screened by the electrons in the grain. This field removes the electrons from donors and leads to the formation of a two-dimensional electron island on the surface of the grain with the size much smaller than the grain size. This effect can be used for creation of small two-dimensional quantum dots. © 2004 American Institute of Physics.
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77.22.Ej Polarization and depolarization
73.21.La Quantum dots

Electron counting of single-electron tunneling current

T. Fujisawa, T. Hayashi, Y. Hirayama, H. D. Cheong, and Y. H. Jeong

Appl. Phys. Lett. 84, 2343 (2004); http://dx.doi.org/10.1063/1.1691491 (3 pages) | Cited 20 times

Online Publication Date: 23 March 2004

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Single-electron tunneling through a quantum dot is detected by means of a radio-frequency single-electron transistor. Poisson statistics of single-electron tunneling events are observed from frequency domain measurements, and individual tunneling events are detected in the time-domain measurements. Counting tunneling events gives an accurate current measurement in the saturated current regime, where electrons tunnel into the dot only from one electrode and tunnel out of the dot only to the other electrode. © 2004 American Institute of Physics.
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73.63.Kv Quantum dots
73.23.Hk Coulomb blockade; single-electron tunneling
73.40.Gk Tunneling

Ultrafast control of electronic motion in quantum-well structures

A. Matos-Abiague and J. Berakdar

Appl. Phys. Lett. 84, 2346 (2004); http://dx.doi.org/10.1063/1.1691191 (3 pages) | Cited 8 times

Online Publication Date: 23 March 2004

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An ultrashort half-cycle pulse (HCP) is a fast (<1 ps) unipolar pulse, followed by a much longer ( ∼ 100 ps) and weaker unipolar pulse of opposite polarity. We show that such pulses can be utilized to localize, within femtoseconds, and control, for picoseconds, the electronic motion in a AlxGa1−xAs based symmetric double quantum well. The results are obtained by (i) deriving analytically for a model system the type of HCPs that lead to a fast and sustainable localization of a desirable final electron state and (ii) by solving numerically exactly the time-dependent Schrödinger equation for the quantum-well structure in the presence of the HCPs. © 2004 American Institute of Physics.
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73.21.Fg Quantum wells
73.20.Fz Weak or Anderson localization

Electrical characterization of phosphorus-doped n-type homoepitaxial diamond layers by Schottky barrier diodes

Mariko Suzuki, Hiroaki Yoshida, Naoshi Sakuma, Tomio Ono, Tadashi Sakai, and Satoshi Koizumi

Appl. Phys. Lett. 84, 2349 (2004); http://dx.doi.org/10.1063/1.1695206 (3 pages) | Cited 21 times

Online Publication Date: 23 March 2004

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Temperature-dependent current–voltage (I–V), capacitance–voltage (C–V) measurements, and frequency-dependent C–V measurements have been carried out to investigate electrical properties of phosphorus (P)-doped n-type homoepitaxial diamond layers. We have fabricated lateral dot-and-plane (with ring-shaped-gap) Schottky barrier diodes. Frequency-dependent capacitance measurements revealed the existence of a deep donor level. C–V measurements deduced that the net donor concentration was 6.2×1017 cm−3 and the corresponding built-in potential was 4.0 eV, when the P concentration was 8.3×1017 cm−3. Phosphorus electrical activity was 0.75 in the P-doped diamond layer. The carrier thermal activation energy (the donor level) was evaluated to be 0.6 eV from the relation between the net donor concentration and the carrier concentration. © 2004 American Institute of Physics.
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85.30.Kk Junction diodes
73.61.Cw Elemental semiconductors
73.30.+y Surface double layers, Schottky barriers, and work functions
61.72.S- Impurities in crystals
71.55.Cn Elemental semiconductors
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